I am willing to help, but I'll need more info about the errors it gives
you said you don't know how to take a screenshots, vista has its own snipping tool that makes it easy (type snipping tool in vista start menu search)
and also, I would need to do if you can play normal video files like avi, and if there are any other problems you've noticed with your os so far.
I am not sure how you came back from windows 7 to vista, seems to me like you just installed vista on top of windows 7
If you run into more problems as you start doing more things, just back up your data and reinstall the os.